﻿#region License
/*
 * Copyright ©2011-2012 EasyMon Project
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *  
 */
#endregion

using System;
using System.Threading;
using EasyMon.Common.Clock;

namespace EasyMon.Win.Agent.Tests
{
    public class ProgrammableClock : IClock
    {
        private readonly ReaderWriterLockSlim _locker = new ReaderWriterLockSlim();

        private TimeSpan _timeShift = TimeSpan.Zero;

        public TimeSpan TimeShift
        {
            get
            {
                try
                {
                    _locker.EnterReadLock();
                    return _timeShift;
                }
                finally 
                {
                    _locker.ExitReadLock();
                }
            }

            set
            {
                try
                {
                    _locker.EnterWriteLock();
                    _timeShift = value;
                }
                finally
                {
                    _locker.ExitWriteLock();
                }
            }
        }

        public DateTime GetCurrentTime()
        {
            return DateTime.UtcNow + TimeShift;
        }
    }
}
